RAMALLAH, West Bank - Israel must halt settlement building and present detailed proposals for a border with a future Palestinian state, visiting U.N. chief Ban Ki-moon said Wednesday, as he tried to persuade the Palestinians to continue low-level meetings with Israel that the international community hopes will evolve into serious negotiations.

Ban praised Palestinian President Mahmoud Abbas for his leadership and publicly backed him on key issues, including the demand for a freeze of settlement building on occupied lands the Palestinians want for their state.

With Abbas by his side, the U.N. chief affirmed that "all Israeli settlements are contrary to international law and prejudice" the outcome of a final peace deal.

At the same time, Ban urged the Palestinian leader not to let the current peace efforts lose momentum. The dialogue on borders and security arrangements began last month at the urging of the Quartet of Mideast mediators — the U.S., U.N., EU and Russia — which asked both sides to submit detailed proposals. The Quartet has said it wants a final deal by the end of the year.